1. Field of the Invention
The present invention relates to a stereoscopic image display apparatus for displaying a stereoscopic image by utilizing an image for a right eye and an image for a left eye, and also relates to a method of manufacturing the stereoscopic image display apparatus.
2. Description of the Related Art
Hitherto, a stereoscopic image display apparatus for displaying a stereoscopic image has been proposed, for example, which is constructed as illustrated in FIG. 6 (see, e.g., Japanese Unexamined Patent Application Publication No. 2002-196281). The stereoscopic image display apparatus, illustrated in FIG. 6, includes an image display panel 51 made of a liquid crystal panel, for example, and a phase difference element 52 disposed on an image output surface side of the image display panel 51. A viewing person looks at display outputs provided by the stereoscopic image display apparatus by using a pair of polarization spectacles 53. In more detail, the image display panel 51 displays an image R for a right eye and an image L for a left eye in a regularly mixed manner in a plane, for example, such that the image R for the right eye and the image L for the left eye are alternately displayed per horizontal line. The phase difference element 52 has a right-eye image display portion 52R corresponding to the image R for the right eye and a left-eye image display portion 52L corresponding to the image L for the left eye. The right-eye image display portion 52R and the left-eye image display portion 52L are alternately arranged per horizontal line. Further, the right-eye image display portion 52R and the left-eye image display portion 52L realize different polarization states, for example, such that the right-eye image display portion 52R provides unidirectional linearly-polarized light (e.g., in a direction climbing to the right), while the left-eye image display portion 52L provides linearly-polarized light (e.g., in a direction climbing to the left) which is rotated through 90° to be perpendicular to the former linearly-polarized light. In combination with the image display panel 51 and the phase difference element 52, the viewing person puts on the polarization spectacles 53 of which right- and left-eye spectacles have different angles of polarization adapted for the corresponding images. Accordingly, the image R for the right eye and the image L for the left eye enter the right eye and the left eye of the viewing person independently of each other. Stated another way, through the right-eye spectacle 53R having the angle of polarization which corresponds to the rightwards climbing direction, the viewing person can see only the image R for the right eye in each odd line, which matches in the angle of polarization with the right-eye spectacle 53R, but is not able to see the image L for the left eye in each even line, which has the angle of polarization rotated through 90° to the leftwards climbing direction by the left-eye image display portion 52L of the phase difference element 52. On the other hand, through the left-eye spectacle 53L having the angle of polarization which corresponds to the leftwards climbing direction, the viewing person can see only the image L for the left eye in each even line, which matches in the angle of polarization with the left-eye spectacle 53L, but is not able to see the image R for the right eye in each odd line, which has the angle of polarization rotated through 90° to the rightwards climbing direction by the right-eye image display portion 52R of the phase difference element 52. Stereoscopic image display apparatuses having other constructions than that described above are also proposed in which left and right images are separately displayed and combined to a stereoscopic image by using polarization spectacles.
In those stereoscopic image display apparatuses, the so-called crosstalk phenomenon may occur. The term “crosstalk phenomenon” implies such a disadvantageous phenomenon that, when the viewing person looks at the image display panel, for example, in an oblique direction not from the front, the image R for the right eye passes through the left-eye image display portion 52L and the image L for the left eye passes through the right-eye image display portion 52R, whereby an image looked at by the viewing person becomes unclear and a stereoscopic effect is reduced.
To prevent the crosstalk phenomenon, a stereoscopic image display apparatus is proposed in which a light shield layer for shielding the light is disposed at the boundary between the right-eye image display portion 52R and the left-eye image display portion 52L of the phase difference element 52 (see, e.g., Japanese Unexamined Patent Application Publication No. 2002-185983). In more detail, for example, when the right-eye image display portion 52R and the left-eye image display portion 52L are alternately arranged per horizontal line, a stripe-shaped light shield layer is arranged to position only in an area with a predetermined width, which includes the boundary between both the display portions 52R and 52L. The light shield layer can be formed, for example, by arranging a black material having a function of shielding the light so as to project on the surface of the phase difference element 52. With the provision of the light shield layer, even when the viewing person looks at the image display panel in an oblique direction, for example, the light is shielded by the light shield layer in such a manner that the image R for the right eye does not pass through the left-eye image display portion 52L and the image L for the left eye does not pass through the right-eye image display portion 52R. Thus, the generation of the crosstalk phenomenon can be prevented.
When the stereoscopic image display apparatus enabling a stereoscopic image to be viewed through the polarization spectacles 53 is constructed, the phase difference element 52 is necessitated to be fixedly arranged on the image output surface side of the image display panel 51. Hitherto, the phase difference element 52 has been fixedly arranged by overlaying the phase difference element 52 on the image display panel 51 with, e.g., magnets interposed therebetween, or by bonding the phase difference element 52 to the image display panel 51 with a suitable bond (see, e.g., Japanese Patent Laid-Open No. 2001-59948 and No. 2001-75048). In one concrete example, the phase difference element 52 can be fixedly arranged by tentatively fixing the phase difference element 52 at its outer peripheral portion with, e.g., magnets or tapes, and then bonding it to the image display panel 51 at four or eight points along the outer peripheral portion of the phase difference element 52 with, e.g., a bond or an ultraviolet curing resin.